Perceived synchrony varies depending on the audiovisual event. Typically, asynchrony is tolerated at greater lead- and lag-times for speech and music than for action events. The tolerance for asynchrony in speech has been attributed to the unity assumption, which proposes a bonding of auditory and visual speech cues through associations in several dimensions. However, the variations in synchrony perception for different audiovisual events may simply be related to their complexity; where speech and music fluctuate naturally, actions involve isolated events and anticipated moments of impact. The current study measured perception of synchrony for long (13 s) and short (1 s) variants of three types of stimuli: (1) action, represented by a game of chess, (2) music, played by a drummer and (3) speech, presented by an anchorwoman in a newscast. The long variants allowed events to play out with their natural dynamics, whereas short variants offered controlled and predictable single actions or events, selected from the longer segments. Results show that among the long stimuli, lead asynchrony was detected sooner for speech than for chess. This contrasts both with previous research and our own predictions, although it may be related to characteristics of the selected chess scene. Interestingly, tolerance to asynchrony was generally greater for short, than for long, stimuli, especially for speech. These findings suggest that the dynamics of complex events cannot account for previously observed differences in synchrony perception between speech and action events.
Research has shown that voicing is difficult to discern in noisy environments. While voicing may be difficult to resolve from visual cues, acoustic cues for voicing are relatively robust. This study addresses these factors with normally aging audiovisual perception. Identification responses were gathered with 19–30-year-old and 49–60-year-old adults for audiovisual (AV) CVs differing in voicing and consonant place of articulation. Materials were presented in quiet and in cafe noise (SNR=0 dB) as audio-only (A), visual-only (V), congruent AV, and incongruent AV. Results show a tendency toward use of visual information with age and noise for consonant place of articulation. Notably for voicing, incongruent AV materials that had one voiced component, regardless if it was A or V that was voiced, were consistently perceived as voiced in both age groups and regardless of noise. Only if the A and V components were both voiceless was the syllable perceived as voiceless. These findings indicate the influence of age and noise in the use of perceptual information to identify place of articulation. That voicing is robustly salient from either audio or visual information, despite the unlikely presence of strong visual cues for voicing, indicates a possible bias toward the perception of voicing.
Rules-of-thumb for noticeable and detrimental asynchrony between audio and video streams have long since been established from the contributions of several studies. Although these studies share similar findings, none have made any discernible assumptions regarding audio and video quality. Considering the use of active adaptation in present and upcoming streaming systems, audio and video will continue to be delivered in separate streams; consequently, the assumption that the rules-of-thumb hold independent of quality needs to be challenged. To put this assumption to the test, we focus on the detection, not the appraisal, of asynchrony at different levels of distortion. Cognitive psychologists use the term temporal integration to describe the failure to detect asynchrony. The term refers to a perceptual process with an inherent buffer for short asynchronies, where corresponding auditory and visual signals are merged into one experience. Accordingly, this paper discusses relevant causes and concerns with regards to asynchrony, it introduces research on audiovisual perception, and it moves on to explore the impact of audio and video quality on the temporal integration of different audiovisual events. Three content types are explored, speech from a news broadcast, music presented by a drummer, and physical action in the form of a chess game. Within these contexts, we found temporal integration to be very robust to quality discrepancies between the two modalities. In fact, asynchrony detection thresholds varied considerably more between the different content than they did between distortion levels. Nevertheless, our findings indicate that the assumption concerning the independence of asynchrony and audiovisual quality may have to be reconsidered.
In many games, a win or a loss is not only contingent on the speedy reaction of the players, but also on how fast the game can react to them. From our ongoing project, we aim to establish perceptual thresholds for visual delays that follow user actions. In this first user study, we eliminated the complexities of a real game and asked participants to adjust the delay between the push of a button and a simple visual presentation. At the most sensitive, our findings reveal that some perceive delays below 40 ms. However, the median threshold suggests that motor-visual delays are more likely than not to go undetected below 51-90 ms. These results will in future investigations be compared to thresholds for more complex visual stimuli, and to thresholds established from different experimental approaches.
The difficulty in detecting short asynchronies between corresponding audio and video signals demonstrates the remarkable resilience of the perceptual system when integrating the senses. Thresholds for perceived synchrony vary depending on the complexity, congruency and predictability of the audiovisual event. For instance, asynchrony is typically detected sooner for simple flash and tone combinations than for speech stimuli. In applied scenarios, such as teleconference platforms, the thresholds themselves are of particular interest; since the transmission of audio and video streams can result in temporal misalignments, system providers need to establish how much delay they can allow. This study compares the perception of synchrony in speech for a live two-way teleconference scenario and a controlled experimental set-up. Although methodologies and measures differ, our explorative analysis indicates that the windows of temporal integration are similar for the two scenarios. Nevertheless, the direction of temporal tolerance differs; for the teleconference, audio lead asynchrony was more difficult to detect than for the experimental speech videos. While the windows of temporal integration are fairly independent of the context, the skew in the audio lead threshold may be a reflection of the natural diversion of attending to a conversation. Index Terms: audiovisual speech, temporal integration, synchrony perception, teleconference
Abstract Social media platforms rely on algorithms to filter and select content, thereby personalizing every individual's social media experience. Many use social media without awareness of this personalization and its impact, pointing to a need to both understand and improve literacy among active social media users. This qualitative study addresses adolescents' social media literacy through an investigation of their experiences with personalization on social media, aiming for a nuanced perspective of their outcomes. A thematic analysis of eight focus group interviews with 47 students aged 15–19 years uncovered two main themes: (1) diverse levels of adolescents' awareness and familiarity with personalization and (2) positive, negative, and mixed emotions toward personalization. Theme one uncovered that although the adolescents were largely unfamiliar with the terminology, when prompted, most of them could provide examples of personalization, whereas theme two revealed that adolescents appreciated relevant content and yet were uneasy about certain features.
With the introduction of The General Data Protection Regulation (GDPR) in 2018, European citizens were granted stronger privacy protection. Despite privacy and GDPR being frequent topics of discussion, many consumers lack knowledge on how personal data are harvested for business purposes, and they are unaware of their rights. Drawing on a larger survey conducted in a Norwegian university college, this study investigates gender differences in privacy behaviour (n=444). We offer three insights. The results revealed that (1) respondents’ concern for privacy does not differ across gender, but men claimed to experience slightly more control over their personal data compared to women. (2) Exercising privacy rights were comparable across gender as women and men reported the same inclination to act on rights granted by GDPR. (3) Willingness to share information in return for benefits depended on the information in question. Men and women agreed in their willingness to exchange name and e-mail. However, women were less willing than men to give up more sensitive information, yet more willing to give up date of birthday, TV viewing history and shopping history. Our insights bring attention to a possible link between experienced control over own data and willingness to exchange data for benefits, highlighting a potential mediating relationship that could be worthwhile pursuing.
